Re: [Qemu-devel] [PATCH for 2.6 v3 1/1] qemu-char: append opt to stop truncation of serial file

[Paolo Bonzini <pbonzini@redhat.com>]

On 04/12/2015 07:42, Denis V. Lunev wrote:
> From: Olga Krishtal <okrishtal@virtuozzo.com>
> 
> Our QA team wants to preserve serial output of the guest in between QEMU
> runs to perform post-analysis.
> 
> By default this behavior is off (file is truncated each time QEMU is
> started or device is plugged).
> 
> Signed-off-by: Olga Krishtal <okrishtal@virtuozzo.com>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Eric Blake <eblake@redhat.com>
> CC: Markus Armbruster <armbru@redhat.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> ---
> Changes from v1:
>   - s/parallels.com/virtuozzo.com/ :(
> 
> Changes from v2:
>   - fixed QAPI description
>   - added has_append filling and checking
> 
> qapi-schema.json |  5 ++++-
>  qemu-char.c      | 14 +++++++++++++-
>  2 files changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 18c9a6c..89201a9 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3020,11 +3020,14 @@
>  #
>  # @in:  #optional The name of the input file
>  # @out: The name of the output file
> +# @append: #optional Open the file in append mode (default false to
> +#          truncate) (Since 2.6)
>  #
>  # Since: 1.4
>  ##
>  { 'struct': 'ChardevFile', 'data': { '*in' : 'str',
> -                                   'out' : 'str' } }
> +                                   'out' : 'str',
> +                                   '*append': 'bool' } }
>  
>  ##
>  # @ChardevHostdev:
> diff --git a/qemu-char.c b/qemu-char.c
> index 2969c44..66703e3 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -3484,6 +3484,9 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend,
>      }
>      backend->u.file = g_new0(ChardevFile, 1);
>      backend->u.file->out = g_strdup(path);
> +
> +    backend->u.file->has_append = true;
> +    backend->u.file->append = qemu_opt_get_bool(opts, "append", false);
>  }
>  
>  static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
> @@ -4041,6 +4044,9 @@ QemuOptsList qemu_chardev_opts = {
>          },{
>              .name = "chardev",
>              .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "append",
> +            .type = QEMU_OPT_BOOL,
>          },
>          { /* end of list */ }
>      },
> @@ -4101,7 +4107,13 @@ static CharDriverState *qmp_chardev_open_file(const char *id,
>      ChardevFile *file = backend->u.file;
>      int flags, in = -1, out;
>  
> -    flags = O_WRONLY | O_TRUNC | O_CREAT | O_BINARY;
> +    flags = O_WRONLY | O_CREAT | O_BINARY;
> +    if (file->has_append && file->append) {
> +        flags |= O_APPEND;
> +    } else {
> +        flags |= O_TRUNC;
> +    }
> +
>      out = qmp_chardev_open_file_source(file->out, flags, errp);
>      if (out < 0) {
>          return NULL;
> 

Queued for 2.6, thanks.

Paolo